Table 6.2. Group 1 systems

DOE-STD-6003-96

TABLE 6.2. Group 1 systems

System

Facility specific function

Potential safety function

Plasma fueling

Provide H/D/T

Primary confinement of tritium

Pumping systems

Maintain specified vacuum and

Primary confinement of tritium

torus exhaust

Plasma heating

Heat plasma to ignition and main-

Primary confinement of tritium

tain driven plasma current

Tritium plant

Separate H/D/T from plasma

Primary confinement of tritium

exhaust; remove tritium from

process streams

Breeding blanket

Breed tritium for fusion reaction;

Primary confinement of tritium;

transfer heat to balance of plant

(depending on design)

Magnet shielding

Shield cryogenic magnets from

Part of biological shield for plant

nuclear heat loads

staff

TABLE 6.3. Group 2 systems

System

Stored energy

Proximity to safety-class SSCs

Plasma

Less than a few GJ

Can focus energy on plasma-facing com-

ponents (e.g., runaway electrons)

Magnets

100s of GJ

Close to cryostat and tritium piping

Vessel cooling

100s of GJ

Close to vacuum vessel

Divertor

10s of GJ

Close to vacuum vessel

Breeding blanket

10s100s of GJ

Close to vacuum vessel and interface to

tritium processing systems

6.5.1 Group 1 Systems

The important design consideration for these systems is that they should be subject to the

same design criteria in performing their public safety function as more visible safety-class sys-

tems, such as the vacuum vessel, while providing primary confinement. Thus plasma-fueling

and vacuum-pumping systems should be designed as safety-class SSCs while performing the

public safety function of tritium confinement if this is shown as required in the safety analysis

process. Parts of these systems not performing public safety functions (e.g., control subsystems

used for the plasma-fueling or vacuum-pumping functions) would not be designated safety-

class. Additional factors to be considered are the presence of new energy sources (e.g., high-

pressure propellant gases, rotating energy of centrifuges, kinetic energy of pellets in plasma-

fueling systems) in these systems and the vulnerable tritium inventory in determining how many

confinement barriers are needed. Designers should try to minimize the portion of these Group 1

systems that supports a public safety function and have clearly defined boundaries between

safety-class and non-safety-class components in such systems. Group 1 systems could

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